The present invention relates to automatic washers, and more particularly to an improved sump for an automatic washer.
Vertical axis automatic washers generally include fluid handling systems for filling a washer tub with a wash fluid (generally a water and detergent solution), holding the wash fluid in the tub during an agitate portion of the wash cycle, and then after the agitation portion of the cycle, draining the wash fluid from the tub. A drain conduit communicates with the lowest portion of the tub to ensure that all of the wash liquid is removed from the tub at the end of the agitate cycle. A subsequent rinse with fresh water and draining of the rinse water are also provided and again the rinse water is drained from the tub through the drain conduit.
In a traditional rinse cycle, at the end of the deep agitation portion of the wash cycle, there is a neutral drain down of the wash liquid and then an extraction of additional wash liquid from the wash load provided by a spinning of the wash basket. Generally, at this time, if desired, fabric softener is introduced onto the wash load. Subsequently, there is a deep water fill, often with cold water, but in some selected instances, with warm water. The level of the deep water fill is based on the original load size selection made by the user. The level of the deep water fill is generally controlled by a level sensor, such as a pressure dome.
After the basket has filled with the rinse water, another agitation occurs for a predetermined short period of time, on the order of one to two minutes and at a predetermined speed depending on the nature of the selected cycle. Agitation is then terminated and another neutral drain down occurs for a predetermined length of time before another spin extraction begins. During the spin extraction there is a step wherein fresh water is applied to the spinning clothes load for a short duration of 15-45 seconds and the released water is directed to drain. The inlet of water is then terminated, but the basket continues spinning. Subsequently there may be up to four additional short (5 second duration) bursts of fresh water applied to the spinning wash load prior to a final spin extraction which continues for a predetermined length of time.
U.S. Pat. No. 4,784,666, assigned to the assignee of the present application, discloses a high performance washing process for vertical axis automatic washers which includes the recirculation of wash fluid prior to the agitate portion of the wash cycle. That patent describes, as a particular embodiment of the invention, to load a charge of detergent into the washer along with a predetermined amount of water, preferably prior to admitting a clothes load into the basket to assure that the concentrated detergent solution will initially be held in a sump area of the wash tub so that the detergent will be completely dissolved or mixed into a uniform solution before being applied to the clothes load. It is also suggested that the addition of an anti foaming agent may be desireable. No particular size or location for the sump is described, in fact, the disclosure describes the washing machine as being a standard, commercially available model, with no structural modifications.